Southwest Airlines hit turbulence yesterday over its plans to enforce a porker-profiling policy that doubles airfares for overweight fliers.

A spokeswoman for Southwest defended the policy and said tubby travelers are treated no differently from “normal” customers.

“We treat them the same way we do our normal customers . . . I apologize – any other customers,” said Southwest’s Christine Turneabe-Connelly, catching her gaffe.

She said the policy will be “fully enforced” as of June 26 because of a new automated boarding system slated to begin then.

Turneabe-Connelly added that the airline doesn’t have set weight or height requirements and that it’s a judgment call made by ticket-takers.

“In some cases, it’s obvious, and in some, there is a question,” she said. “But our service agents are trained . . . how to assess and address the situation in the most discrete way possible.”

Southwest toughened its policy because other passengers complained they were being squished by more corpulent customers.

For their double fare, fat fliers won’t be allowed to double their baggage allowance or their snacks.

Tourist-class seats on most airliners are 17 to 18 inches wide.

The Dallas-based airline has had a policy for more than 20 years charging larger passengers for two seats, but has allowed leeway in applying it.

So far, Southwest is alone on the policy. United Airlines spokesman Chris Brathwaite said its policy is that a customer can buy an extra seat, but the carrier leaves it to the flier’s discretion.

Southwest’s policy is leaving a bitter taste in the mouths of advocates for the acceptance of overweight people. Lynne McAfee, of the Council on Size and Weight Discrimination, said Southwest has always been biased against big.

“Southwest has always been the most disrespectful airline to fat people. We’ve had loads of complaints about them,” McAfee said. “Fat people are pretty much at the mercy of disgruntled ticket-takers.”